This invention relates to devices for enclosing elongate objects for example pipes or cables and in particular to dimensionally-recoverable devices for enclosing such objects.
Dimensionally-recoverable wrap-around devices have become widely employed for sealing, insulating or otherwise protecting a substrate where the use of a preformed tubular cover, such as a sleeve, is not possible or convenient, for example where the end of an elongate substrate is not accessible. In general, a wrap-around device comprises a cover which is adapted to be wrapped around the substrate to be enclosed, and a closure arrangement for securing the cover in tubular form about the substrate. After being secured about the substrate, the cover may be recovered onto the substrate by the application of heat or by another appropriate method. Examples of wrap-around devices are described in U.S. Pat. Nos. 3,379,218, 3,455,336, 3,530,898, 3,542,077, U.K. Patent Specification No. 1,561,125 and in German Offenlegungsschrift No. 1,947,057, the disclosures of which are incorporated herein by reference.
Whilst the above wrap-around devices are suitable for enclosing straight substrates of generally uniform dimensions, no previously proposed device is entirely satisfactory for sealing a substrate against ingress of fluids, where the shape or dimensions of the substrate vary abruptly, for example where a tubular substrate has a sharp bend or branch e.g. in the form of a "T", or where the substrate is in the form of a "transition", i.e. where the diameter of the substrate increases or decreases abruptly along its length. It has been found that the closure arrangements of such substrates either are not susceptible to being located about abrupt changes in the surface of the substrate or, if they are, cannot form a reliable seal against ingress of fluids.